Inflatable structures used with projection or imaging screens are known in the art. United States Patent Publication 20100007949 and U.S. Pat. No. 7,446,937 describe examples of inflatable screens. Inflatable screen devices can be quite large and are often used in outdoor environments. Therefore, the stability of inflatable screens is important.
Inflatable screen devices generally include an inflatable framework that is used to hold up and secure the screen surface. The inflatable structure may be held to the ground by guy wires or tethers that run from the inflatable structure to anchor points on or in the ground or ballast. This prevents the inflatable structure from moving along the ground or falling. However, the screen surface and/or framework may bend, curve, or bow due to structural design, large size, torsion (i.e., when the weight is different on the front and back of structure), and the influence of wind. It is highly desirable for the screen projection surface to remain flat and rectangular during use so that the projected images appearing on the screen are not distorted. Prior art attempts to keep screen projection surfaces flat and rectangular during use have included structural elements, such as one or more support columns centered or distributed vertically in the framework. In the prior art, these elements have been placed in or close to the plane of the framework and the projection screen surface to reduce some of the displacement of the framework and screen due to wind or other forces. In the prior art designs, the screen surface may come into contact with such a support structure as the wind pushes against the screen from the front, which can cause visually apparent distortion of the projection screen surface and projected images.
Thus, a need exists for a support mechanism for inflatable screen devices that reduces displacement and distortion of the framework and projection screen surface due to wind or other forces while minimizing interference with the screen when the wind pushes against the screen surface from the front.